(Hyacinth family)

This family, members of which were formerly classified in the Liliaceae, comprises about 770 species of bulbous or rhizomatous herbs in 41 genera. They are found mainly in the Mediterranean region and in South Africa (Mabberley 1997). Many are to be found in cultivation as ornamentals, including representatives from the genera Bellevalia Lapeyr., Bowiea Harvey ex Hook.f., Chiondoxa Boiss., Eucomis L'Hér., Galtonia Decne., Hyacinthus L., Ledebouria Roth, Muscari Mill., Ornithogalum L., and Scilla L.

Several members of this family have skin irritant properties that may be ascribed to their content of calcium oxalate needle crystals (raphides). In some species, the mechanical injury to the skin seems to be aggravated by irritant chemicals in the plant sap. An allergic reaction may be superimposed on the mechanical/chemical injury, but this seems to be the exception rather than the rule. The identity of the irritant or allergenic chemicals has not been established. Florists, nurserymen, gardeners, and others who handle or grow these plants are at risk of developing dermatitis. The traditional dermatological uses of plants in this family include uses that exploit the irritancy, but also uses where irritancy would not explain the intended therapeutic outcome, for example where a lotion for sore eyes is prepared, or where an application for boils and sores is prepared.

Bowiea volubilis Harvey ex Hook.f.

Climbing Green Lily

This plant is a native of south and East Africa. In the traditional medicine of this region, an infusion of the crushed bulb is used to prepare a lotion for sore eyes and for skin diseases (Hulme 1954).

There are about 120 species of Drimia, natives of the Mediterranean region, Africa and Asia (Mabberley 1997). Plants formerly considered to belong to the genus Urginea Steinh. are now classified as Drimia species.

In the traditional medicine of southern Africa, the fleshy scales of the bulb are heated and applied to gouty limbs and rheumatic swellings. The relief is probably due to the heat but may be due to irritation (Watt & Breyer-Brandwijk 1962).

Drimia ciliaris Jacq. ex Willd.

(syns Hyacinthus ciliaris Poir., Idothea ciliaris Kunth)

Itch-Bulb

The bulb is highly irritant when handled, the irritation being ascribed to the presence of calcium oxalate raphides. The juice is said to blister the skin (Watt & Breyer-Brandwijk 1962).

This plant is the source of the crude drug Indian Squill, otherwise known as Urginea, which may be used as a substitute for Squill derived from Drimia maritima Stearn (see below). According to Nadkarni (1976), powdered Indian squill is locally applied to remove warts. Behl et al. (1966) also refer to the skin irritant properties of Indian Squill.

This is the source of the crude drug Squill, otherwise known as White Squill or Scillae Bulbus, which has been used medicinally from a very early period (Stannard 1974). Squill contains the glycosides scillarin A and B, which resemble the cardiac glycosides found in digitalis (Gemmill 1974). These glycosides are poorly absorbed when administered orally. They have an expectorant effect in small doses and produce emesis in larger doses (Todd 1967).

A red-coloured variety, which is found in North Africa, is known as Red Squill. It has long been used as a rat poison (Todd 1967). Schwartz et al. (1947) documented the belief held by some authorities that the juice of Scilla rubra is a cutaneous irritant to everyone, whilst contact with the leaves irritates only sensitised individuals.

In a study of the use of medicinal plants in the Palestinian West Bank region, Ali-Shtayeh et al. (2000) recorded that Urginea maritima was a popular remedy for treating skin disorders, but provided no detail as to the method of use nor the nature of the skin disorders treated.

Pereira (1842) recorded that fresh Squilla maritima bulb, when applied to the skin, causes irritation, inflammation, even vesication - attributes also noted by Chevalier (1933) and by Schwartz et al. (1947). Powdered squill can cause severe keratoconjunctivitis and iritis (Achermann 1928). Biberstein (1927) observed a positive patch test reaction to this plant (which he identified as Scilla maritima) in a young child who reacted also to an unidentified species of Tradescantia L. (fam. Commelinaceae) and to a plant believed to be Lamium galeobdolon L. (fam. Labiatae). Touton (1932) referred to other reports (Hoffmann 1904a, Hoffmann 1904b, etc.) in the early German literature of dermatitis attributable to the topical use of the leaves or crushed bulbs of Scilla maritima to treat skin conditions, drawing attention to the possible contribution made by calcium oxalate raphides to the skin reaction produced by the plant. He referred also to cases of occupational dermatitis in a factory handling crude drugs.

Hyacinthus L.

The 3 species in this horticulturally important genus are natives of the West and Central Asia. Several species are cultivated, but by far the most popular is Hyacinthus orientalis L., which was first developed by artificial selection in Turkey and subsequently in Holland (Gorer 1970). Hyacinthus orientalis, the so-called common hyacinth, is now one of the most commonly cultivated bulbs for indoor and outdoor decoration, and workers in the bulb industry, gardeners, florists and housewives may all be exposed in some degree to a dermatitis hazard. Hyacinthus romanus L. (Roman hyacinth) is also quite frequently cultivated.

Bulb growers are often aware that some cultivars of H. orientalis are more likely to cause trouble than others: L'Innocence, Marconi, Carnegie and City of Harlem were considered particularly liable to cause dermatitis (van der Werff 1959).

Experiments reported by Morris (1897), corroborated by Scott (1897), had demonstrated that both dry and moist scales from the bulbs of the common hyacinth (Hyacinthus orientalis and varieties) were capable of producing considerable irritation when applied directly to the skin. This irritation was caused, evidently, by calcium oxalate raphides varying from 1/100 to 1/200th of an inch [= 250–125 μm) in length. Roman hyacinths (variety albulus) were understood to cause greater irritation than other varieties. About 6% of calcium oxalate is present in bulb scales and a similar concentration has been found in the dust on tables used for sorting and packing (Hjorth and Wilkinson 1968).

Hyacinths also probably contain allergenic substances, which have not been identified. Fungi, parasites, fungicides and pesticides must also be considered (van der Werff 1959).

Oil of Hyacinth, which is used in perfumes, has caused allergic dermatitis (Varga 1936). Hyacinthin is phenylacetaldehyde (Furia & Bellanca 1971). Oil of Hyacinth contains some known sensitisers.

Schwartz et al. (1947) described hyacinths, and especially the Dutch hyacinth as a cause of occupational dermatitis in florists and others who handle the bulbs. Harrison (1906) included Hyacinthus orientalis in a list of plant, etc. which may cause dermatitis. McCord (1962) also referred to hyacinths as a cause of occupational dermatitis.

Hyacinth bulb dermatitis is predominantly of irritant type, and is very familiar to nurserymen. However the irritant properties of the bulbs are such that it is often difficult to confirm the suspected coexistence of allergic dermaitis, sometimes suggested by the clinical features.

Referring to Scilla lanceaefolia, Watt & Breyer-Brandwijk (1962) recorded that in the traditional medicine of southern Africa, the bulb is used as a local irritant. They noted also that an infusion prepared from the plant is used to bathe skin eruptions, and that the burnt and powdered plant is applied in an ointment to wounds and sores.

Merwilla natalensis Speta

(syn. Scilla natalensis Planchon)

Blue Squill, Blue Hyacinth

Referring to Scilla natalensis, Watt & Breyer-Brandwijk (1962) noted that in the traditional medicine of southern Africa, a hot lotion made by boiling the cut-up bulb in water is used as an application to boils and veld sores.

Muscari Mill.

There are about 30 species, natives of the Mediterranean region and west Asia (Mabberley 1997). Many species are popular garden plants, known collectively as grape hyacinths.